The B.League is a men's professional basketball league in Japan. The league is operated by the Japan Professional Basketball League and was formed as a result of a merger between the National Basketball League that was operated by the FIBA-affiliated Japan Basketball Association and the independently operated bj league. The merger had been mandated by FIBA as a condition to Japan having its membership resumed following suspension in November 2014. The league began play in September 2016.
History
Background The Japan Basketball Association was formed in 1930 and has operated Japan's top basketball leagues under various names since 1967. Throughout the history of the association, teams have been affiliated with large corporations and players have been employed by their respective owner company rather than competing as professional basketball players. In the early 1990s soccer in Japan moved away from a similar corporate structure and launched the J.League in 1993. The JBA commenced investigating the professionalization of basketball in the same year, and in 1997 lifted the ban on professional players. Despite this, the structure of the Japan Super League remained amateur in nature, with most teams remaining under the control of a corporate sponsor/owner.
In 2005 a rival bj league was launched in competition with the Super League, based on an American franchise system of professional teams. In response, the JBA re-launched the Super League as the Japan Basketball League (JBL) in 2007, but there was still a mixture of professional and corporate teams in the competition. The JBL was again rebranded as the National Basketball League in 2013. Since the establishment of the bj league in 2005, both competitions rapidly expanded the number of teams, with 45 teams participating between the two competitions in 2015.
FIBA, the international governing body for basketball, grew concerned with the division and disorganization of the sport within the country. After the JBA failed to comply with deadlines to commence reorganizing the domestic leagues, FIBA suspended Japan from international competitions in November 2014. A task force to investigate the reformation of the domestic leagues was formed and Saburō Kawabuchi was appointed co-chairman. In May 2015, upon FIBA's recommendation, Kawabuchi was appointed as president of the JBA. The merger of the two competing leagues into the B.League was announced in June 2015 and the international suspension was lifted by FIBA in August. Telecommunications company Softbank was named as the league's top sponsor for the inaugural season in March 2016.
2016–2026: First decade
The 2016–17 season commenced with an inaugural match between four-time JBL/NBL champions Alvark Tokyo, who finished on top of the NBL ladder in 2015–16, and four-time bj-league champions Ryukyu Golden Kings, who won the 2015–16 bj-league championship, at Yoyogi National Gymnasium on 22 September 2016. A full round of games involving all other teams commenced on September 24.
Since the 2021–22 season, the winners and runners-up of each season qualify for the East Asia Super League.
2026–present: Restructuring Starting from the 2026–27 season, the B.League will undergo a major structural change. The top division, B1, will be renamed to B.League Premier with 26 permanent member teams and no promotion and relegation between it and the lower divisions. For competitive balance, a salary cap of 800 million will be implemented, and the highest-paid player on each team will count as 150 million towards the cap even if the player's salary is higher. The lower divisions, B2 and B3, will be renamed to B.League One and B.League Next, respectively.
Season format Starting from the 2026–27 season, the B.League will consist of three divisions. The highest division is B.League Premier, composed of 26 teams split into two conferences. The second division is B.League One, composed of 25 teams split into five conferences. The third division is B.League Next, currently composed of four teams. Each league has specific requirements for teams to be licensed to compete in each division.
The formats for each new division have yet to be unveiled. For reference, these were the formats of the two highest divisions in the 2025–26 season:
First Division (B1) In the first division, each team plays a 60-game regular-season schedule that consists of 36 games against teams within their conference (4 games against each team) and 24 games against teams in the other conference (2 games against eight teams and 4 games against the remaining two teams). Eight teams qualify for the playoffs, including the top three teams from each conference, and the next two teams with the best records, regardless of their conference, as wild cards. The playoffs consist of the quarterfinal, semifinal, and final rounds, with a best-of-three format in each round. Each round is played at the team's home court, which finished with the higher winning percentage during the season.
Second Division (B2) In the second division, the regular season will also consist of a 60-game schedule, but with 42 games against teams within their own conference (6 games against each team) and 18 games against teams in the other conference (2 games against seven teams and 4 games against the remaining team). The playoff qualification and match format is identical to the first division: Eight teams qualify for the playoffs, which includes the top three teams from each conference, and the next two teams with the best records, regardless of their conference, as wild cards. The playoffs consist of quarterfinal, semifinal, and final rounds, with a best-of-three format in each round. Each round is played at the home court of the team that finished with the higher winning percentage during the season.
Current clubs In the 2014–15 season, there were 12 teams in the NBL, 10 teams in the National Basketball Development League (NBDL, the NBL's second division league) and 24 teams in the bj-league. All 46 teams sought entrance to the B.League's inaugural 2016–17 season, along with the Wakayama Trians, who withdrew from the NBL in January 2015 due to financial difficulty. Ultimately, all clubs were accepted into the league except for the Trians and the Hiroshima Lightning, who were in their first season as a bj-league expansion club. The allocation of the 45 teams into three divisions was announced in two phases in July and August 2015. In April 2016 the league announced rules regarding official team names, shortened names and abbreviations to be used by the clubs. A list of names to be used by each club in the 2016–17 season was also published. Beginning in the 2020–21 season, the B.League was reformatted to only have two conferences each, East and West, in the first and second divisions. However, the first division reverted to a three-conference system, East, Central, and West, beginning in the 2022–23 season.
On October 31, 2025, the league announced the divisions of all 55 member teams at that time, with 26 teams assigned to Premier, 25 assigned to One, and only four to Next.
B.League Premier (26 teams)
Conference Team Location Arena Capacity Founded Joined East Akita Northern Happinets Akita, Akita CNA Arena Akita 5,000 2010 2016 Altiri Chiba Chiba, Chiba Chiba Port Arena 7,512 2020 2021 Alvark Tokyo Kōtō, Tokyo Toyota Arena Tokyo 10,000 1948 2016 Chiba Jets Funabashi, Chiba 11,000 2005 2016 Gunma Crane Thunders Ōta, Gunma 5,000 2011 2016 Ibaraki Robots Mito, Ibaraki Adastria Mito Arena 5,000 2013 2016 Kawasaki Brave Thunders Kawasaki, Kanagawa Kawasaki Todoroki Arena 6,500 1950 2016 Levanga Hokkaido Sapporo, Hokkaido Hokkai Kitayell 8,000 2006 2016 Sendai 89ers Sendai, Miyagi Xebio Arena Sendai 5,038 2005 2016 Tokyo Sunrockers Kōtō, Tokyo Toyota Arena Tokyo 10,000 1935 2016 Toyama Grouses Toyama, Toyama Toyama City Gymnasium 5,006 2005 2016 Utsunomiya Brex Utsunomiya, Tochigi Brex Arena Utsunomiya 2,900 2007 2016 Yokohama B-Corsairs Yokohama, Kanagawa Yokohama International Swimming Pool 5,000 2010 2016 West Hiroshima Dragonflies Hiroshima, Hiroshima Hiroshima Sun Plaza 6,052 2013 2016 Kobe Storks Kobe, Hyogo 10,168 2011 2016 Kyoto Hannaryz Kyoto, Kyoto Kyoto City Gymnasium 4,000 2009 2016 Nagasaki Velca Nagasaki, Nagasaki 6,000 2020 2021 Nagoya Diamond Dolphins Nagoya, Aichi IG Arena 17,000 1950 2016 Osaka Evessa Osaka, Osaka Ookini Arena Maishima 7,056 2004 2016 Ryukyu Golden Kings Okinawa, Okinawa Okinawa Suntory Arena 10,000 2007 2016 Saga Ballooners Saga, Saga 8,400 2018 2019 San-en NeoPhoenix Toyohashi, Aichi Toyohashi City General Gymnasium 3,500 1965 2016 SeaHorses Mikawa Kariya, Aichi Wing Arena Kariya 2,376 1947 2016 Shiga Lakes Ōtsu, Shiga 5,000 2008 2016 Shimane Susanoo Magic Matsue, Shimane Matsue City General Gymnasium 4,550 2009 2016 Shinshu Brave Warriors Chikuma, Nagano White Ring 7,000 2011 2016
B.League One (25 teams)
Conference Team Location Arena Capacity Founded Joined North Aomori Wat's Aomori, Aomori 2,596 2012 2016 Fukushima Firebonds Kōriyama, Fukushima Horaiya Bonds Arena 5,013 2013 2016 Iwate Big Bulls Morioka, Iwate Morioka Takaya Arena 5,058 2010 2016 Koshigaya Alphas Koshigaya, Saitama Koshigaya Municipal General Gymnasium 4,472 1997 2016 Yamagata Wyverns Tendō, Yamagata Yamagata Prefectural General Sports Park Gymnasium 3,976 2009 2016 East Earthfriends Tokyo Z Ōta, Tokyo Ebara Wave Arena Ota 4,012 2014 2016 Saitama Broncos Tokorozawa, Saitama 1,374 1982 2016 Tachikawa Dice Tachikawa, Tokyo Arena Tachikawa Tachihi 3,000 2021 2022 Tokyo Hachioji Bee Trains Hachiōji, Tokyo Ésforta Arena Hachiōji 2,000 2012 2016 Tokyo United BC Kōtō, Tokyo Ariake Arena 15,000 2021 2022 Central Fukui Blowinds Fukui, Fukui 3,975 2023 Gifu Swoops Gifu, Gifu OKB Gifu Seiryu Arena 3,500 2003 2018 Kanazawa Samuraiz Kanazawa Ishikawa Kanazawa City General Gymnasium 2,312 2015 2016 Niigata Albirex BB Nagaoka, Niigata City Hall Plaza Aore Nagaoka 5,000 1954 2016 Yokohama Excellence Yokohama, Kanagawa 3,000 2002 2016 West Bambitious Nara Nara, Nara Rohto Arena Nara 2013 2016 Fighting Eagles Nagoya Nagoya, Aichi Biwajima Sports Center 1957 2016 Tokushima Gambarous Tokushima, Tokushima 4,200 2022 2023 Tryhoop Okayama Okayama, Okayama Shigeto Arena Okayama 11,000 2018 2019 Veltex Shizuoka Shizuoka, Shizuoka Shizuoka City Central Gymnasium 984 2018 2019 South Ehime Orange Vikings Matsuyama, Ehime Matsuyama City General Community Center 2005 2016 Kagawa Five Arrows Takamatsu, Kagawa Takamatsu City General Gymnasium 2006 2016 Kagoshima Rebnise Kagoshima, Kagoshima Kagoshima Arena 5,000 2008 2016 Kumamoto Volters Kumamoto, Kumamoto Kumamoto Prefectural Gymnasium 4,110 2012 2016 Rizing Zephyr Fukuoka Fukuoka, Fukuoka Teriha Sekisui House Arena 5,042 2006 2016
B.League Next (4 teams)
Team Location Arena Capacity Founded Joined Shinagawa City BC Shinagawa, Tokyo Shinagawa City Togoshi Gymnasium 424 2012 2021 Veertien Mie Basketball Yokkaichi, Mie 3,000 2020 2022 Wolga Shonan Fujisawa, Kanagawa 3,000 2020 2022 Yamaguchi Patsfive Yamaguchi, Yamaguchi 3,000 2020 2021
Champions and finals Numbers in brackets denote the team's seed in its conference from the regular season.
First division finals +SeasonChampionsRunners-upFinals score2016–17Link Tochigi Brex (2)Kawasaki Brave Thunders (1)85–792017–18Alvark Tokyo (3)Chiba Jets (2)85–602018–19Alvark Tokyo (4)Chiba Jets (1)71–672019–20Cancelled due to the COVID-19 pandemic2020–21Chiba Jets (2)Utsunomiya Brex (1)2–1 (best-of-three series)2021–22Utsunomiya Brex (2)Ryukyu Golden Kings (1)2–0 (best-of-three series)2022–23Ryukyu Golden KingsChiba Jets 2–0 (best-of-three series)2023–24Hiroshima DragonfliesRyukyu Golden Kings2–1 (best-of-three series) 2024–25Utsunomiya BrexRyukyu Golden Kings2–1 (best-of-three series) 2025–26Nagasaki VelcaRyukyu Golden Kings2–1 (best-of-three series)
Second division finals